Field of the Invention
The present invention relates to a defoamer adjuvant that has a polyalkylene glycol containing butylene oxide adsorbed onto a solid carrier particle.
Introduction
Concentrates are a convenient and economical way to sell active components for formulations such as agrochemicals. Concentrates can be shipped with a minimal amount of carrier fluid, such as water, and then diluted in a carrier just prior to use by a consumer. That allows the manufacturer to avoid shipping water. However, consumers end up having to mix up their own formulations by mixing concentrate and carrier to achieve a usable formulation. That process can often result in foam formation during the mixing process, which can undesirably cause delays in preparing formulation and even loss of active if the foam froths out of the intended container. As a result, it is common for manufacturers to include defoamers in concentrate formulations to inhibit foam formation during dilution with a carrier.
Common defoamers for use in concentrates include organosilicone agents, perfluoroalkyl defoaming agents, and acetylenic diols. Organosilicone agents tend to be expensive and can decompose under conditions used to prepare solid formulations, thereby losing efficacy as a defoamer. Moreover, organosilicone agents tend to create cloudy solutions, which make them undesirable for clear formulations. Perfluoroalkyl defoaming agents and acetylenic diols are effective defoamers in liquid formulations, but are less effective as a solid adjuvant and can bind up so tightly as to lose their defoaming efficacy. Propylene oxide (PO) or PO and ethylene oxide (EO) copolymers have also had some reported success as defoamers.
It is desirable to identify a defoamer that is less costly than organosilicone defoamers, that is particularly effective as a solid adjuvant unlike perfluoroalkyl defoaming agents and acetylenic diols and that is more effective as a defoamer than PO and EO/PO copolymers.